Malicious PDF — malware analysis report

Static analysis result for SHA-256 c645d5504ca73140…

MALICIOUS

PDF

92.6 KB Created: 2021-06-26 20:55:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 79fe964491ca0e52be46fcd8035a50a3 SHA-1: cda28e5f9fb4dbd9296b2a8e2223236d7e781de2 SHA-256: c645d5504ca7314013745667293ca56fe8c6f57d305107e9323d285f41eaaa64
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous links pointing to compromised WordPress upload directories, indicating it functions as a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the presence of multiple links to potentially malicious or compromised sites suggests an intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a166af2d3b9---gigikanomutu.pdf
    • https://arerp.kr/data/file///79204258753.pdf
    • http://optikametuje.cz/userfiles/file/39004816633.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16088dc9297d2a---15014612929.pdf
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160703f106495c---tumiwuvanefoterelirujinex.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608af4038892c---zojadijulenakogi.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160711c3c4cfcc---49825726740.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb45ea278a---99390085191.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa851db3088---72545426345.pdf
    • https://artenika.pl/fck/file/71495787244.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160735e2825afd---71062532229.pdf
    • http://aclamerica.com/customers/CMS-IMAGES/file/geridanubalisizakalupobi.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/d96679d67f827f5307722e4634e70ef8/xijudorolejozukigoke.pdf
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/00ee5344d070dfe78405f3f0e2ed3fa0/76619241705.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/f91b832f0e3aa6664fcafc76933d0205/17727438022.pdf
    • http://alt-1c.ru/userfiles/file/vodiwinawaraxijon.pdf
    • https://audreyheselmans.com/_files/file/jelijamuxeve.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc11e6b4d1---binodowenilomefob.pdf
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160945afb034c1---fowabomegufofajubemejobe.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5e0517d4b---dinilikekoduzopisebi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=triangle+and+its+properties+class+7+worksheets+pdf+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000edfe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFE 16792 bytes
font_01_sfnt_off00010610.bin
6dcf3977bc305f750214cdc6a7c343efa2f5e6ee571d2c9b3f2f5c07f551cd59
pdf-font-stream PDF embedded font (sfnt) at offset 0x10610 17932 bytes
font_02_sfnt_off00013565.bin
450eea5fc67953cc3bdc764260aa6f1739571c17331c9588074966c3dbef4c6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x13565 16088 bytes
font_03_sfnt_off00014a9b.bin
38646a7f9057917ec489472c75c5d4402faa8e7ce0542a505149a0fa67a407ce
pdf-font-stream PDF embedded font (sfnt) at offset 0x14A9B 11088 bytes